you can create a energy being known as a thought-form, also known as servitor, which does a specific task you program it to do. If however you are looking for magickal help i will advise getting a familiar.
A familiar is an animal whether physical or spiritual that takes the role of assisting you in your projection of energy in your workings. Common servitors are known to be, snakes,cats,dogs,wolves,owl,rat,raven/magpie other animals as well. It does not mean any animal can't be your servitor, but it is important to know that these animals choose you and not vice versa. They are to be treated with utmost respect.
How to get a familiar?
well firstly i personally speaking to eiskora a moderator on this site, she as an excellent knowledge on familiars herself.
This two methods i personally can recommend.
For a physical animal
before doing anything magickal, establish a bond between you and the animal, if its your pet then better yet. be known some animals may come to you on their own waiting for you to realize that they are your familiar. If you have a connection to nature (which you should have in dealing with familiars) you can ask the animal if it wants to accompany you as a familiar. The animal will not physcially talk of course but there is a language in which the animal replies you can hear sound combined with imagery
If the animal agrees you can call upon the elements to bless the animal in doing this, still many witches believe that a familiar should never be a pet. I personally think just treat it with respect.
Step one: gather your items that represent the elements which should be contained in a circle or pentacle. Gather a crystal, special stone, or salt to represent earth, a candle to represent fire, a small bowl or glass of water to represent the water element, and incense to represent air.The element spirit is always present as your thought and will.
Step two: Cleanse the space you are going to work in and proceed by chanting: I invoke the power of the elemental forces nature, in the name of the creator/goddess (whomever you call) i ask that you bless this being of your creation to assist me in path. Let the beasts of the heavens and the earth bear witness and grant upon me their comfort and show unto me the ways of their speech.
Open the 7 channels of my body to receive the bounty around me, so mote it be!
Lastly take your right index finger and touch the animal's forehead and touch your third eye area, signifying the psychic relation ship between the witch and companion.
For a spiritual animal
there are familiars that can be in spirit form, which in most cases nowadays where physical animals can't be attained this is an excellent alternative. This method works for both physical and spiritual ones actually, i like this method allot more.
Sit in your meditation and call one to your self.
step one: Cleanse the area you are going to meditate in just in case it has negative energy. Then proceed.
When you have gotten into a relaxing position, visualize your self in a void of darkness, spend sometime in this darkness acknowledging its creative energy, open yourself nature now allow your heart to expand, focus entirely on your heart, let a green wave of energy overtake the darkness with a strong feeling of pure love. After this has been established visualize the waves reversing giving a calling to a familiar , don't focus on any animal in particular just let them come to you.
visit this link to read more on familiars: http://www.witchs-brew.org/shadows/animals/familiar.html